1. Field of the Invention
The invention relates to a method of making a relay.
2. Description of the Related Art
As shown in FIG. 1, a conventional method of making a relay 10 (see FIG. 9) comprises steps 21 to 26.
As shown in FIGS. 1 and 2, the step 21 is to prepare a relay core member 11 including a base plate 111 that extends in a horizontal direction (X) and that is formed with a through hole 116, a top plate 112 that extends in the horizontal direction (X) and that is spaced apart from the base plate 111 in a vertical direction (Y), a coil unit 110 that extends in the vertical direction (Y) and that is disposed between the base and top plates 111, 112, and a connecting plate 114 that interconnects the base and top plates 111, 112 and that is disposed between the coil unit 110 and the through hole 116. The coil unit 110 includes a core 113, a coil 12 wound on the core 113, and a pair of rods 115, each of which is coupled to the coil 12 and extends through the base plate 111.
As shown in FIGS. 1, 3, and 4, the step 22 is to prepare a first terminal 13 that has a first terminal portion 131 formed with a plate engaging notch 1310, a first fixed portion 132 extending perpendicularly from one edge of the first terminal portion 131, and a first contact 133 disposed on the first fixed portion 131, and to couple the first terminal 13 to the relay core member 11 by moving the first terminal 13 horizontally relative to the relay core member 11 such that the plate engaging notch 1310 engages the base plate 111 of the relay core member 11, that a portion of the first terminal portion 131 extends downwardly relative to the base plate 111, and that the first fixed portion 132 extends horizontally above the top plate 112 of the relay core member 11.
As shown in FIGS. 1, 5, and 6, the step 23 is to prepare a second terminal 14 that has a second terminal portion 141, a resilient portion 142 extending perpendicularly from one edge of the second terminal portion 141, a second contact 143 disposed on the resilient portion 142, a pair of opposite wing portions 144 formed at two sides of the second terminal portion 141, and a pair of tongue pieces 145 formed respectively at the wing portions 144, and to couple the second terminal 14 to the relay core member 11 by moving the second terminal 14 vertically relative to the relay core member 11 such that the second terminal portion 141 extends downwardly through the through hole 116 in the base plate 111, that the resilient portion 142 extends horizontally above the top plate 112 and the first fixed portion 132 of the first terminal 13, and that the second contact 143 is registered with the first contact 133 of the first terminal 13. After the second terminal 14 is coupled to the relay core member 11, an operator has to fold each of the wing portions 144 manually toward the connecting plate 114 with the use of a tool (not shown) such that the tongue pieces 145 engage respectively opposite sides of the connecting plate 144, thereby positioning the second terminal 14 relative to the relay core member 11.
As shown in FIGS. 1, 7, and 8, the step 24 is to prepare a third terminal 15 that has a third terminal portion 151 formed with plate engaging notches 1510, 1511, a second fixed portion 152 extending perpendicularly from one edge of the third terminal portion 151, and a third contact 153 disposed on the second fixed portion 152, and to couple the third terminal 15 to the relay core member 11 by moving the third terminal 15 horizontally relative to the relay core member 11 such that the plate engaging notches 1510, 1511 respectively engage the top and base plates 112, 111 of the relay core member 11, that a portion of the third terminal portion 151 extends downwardly relative to the base plate 111, that the second fixed portion 152 extends horizontally above the resilient portion 142 of the second terminal 14, and that the third contact 153 is registered with the second contact 142.
The step 25 is to test the resiliency of the resilient portion 142 of the second terminal 14 via a testing instrument (not shown). If the testing result does not fall within the standard range, the operator has to adjust manually the resilient portion 142 with the use of a tool so as to meet the standard requirement.
As shown in FIGS. 1 and 9, the step 26 is to enclose the relay core member 11, the first terminal 13, the second terminal 14, and the third terminal 15 within a housing 16, and to seal the housing 16 with resin 17 filled between the housing 16 and the base plate 111 of the relay core member 11.
In use, the second contact 143 of the second terminal 14 contacts the third contact 153 of the third terminal 15 to form a first circuit when current does not flow through the coil unit 110. When current flows through the coil unit 110, an electromagnetic field is generated to attract the resilient portion 142 of the second terminal 14 such that the second contact 143 is separated from the third contact 153 and contacts the first contact 133 of the first terminal 13, thereby forming a second circuit.
However, since the second terminal 14 is vertically coupled to the relay core member 11, and since the tongue pieces 145 will affect vertical movement of the second terminal 14 if the wing portions 144 are folded prior to coupling the second terminal 14 to the relay core member 11, the second terminal 14 has to be assembled manually. Moreover, since the resiliency of the resilient portion 142 of the second terminal 14 may deviate from the standard range during manual assembly of the second terminal 14, the step 25 of testing the resiliency of the resilient portion 142 of the second terminal 14 after coupling to the relay core member 11 is required. Therefore, the conventional assembling method results in a relatively high cost of manufacture. Furthermore, if the tolerance range of the through hole 116 in the base plate 111 of the relay core member 11 is too large, the second terminal portion 141 of the second terminal 14 may not be properly assembled relative to the relay core member 11 since the second terminal portion 141 extends loosely through the through hole 116, such that the operator has to spend more time to assemble properly the second terminal 14, thereby resulting in higher manufacturing costs.